10 welding technologies at the edge of the possible

Recently I watched “How rockets are made” by Destin Sandlin. In this video, Destin presents a tour of United Launch Alliance‘s rocket factory in Decatur, Alabama, together with ULA’s CEO, Tory Bruno. If you are at all interested in either aerospace, rockets, or manufacturing, I highly recommend watching Destin’s video:

How rockets are made. A United Launch Alliance rocket factory tour with Destin Sandlin and Tory Bruno.

As I watched the video, I was particularly fascinated by the various welding technologies that ULA uses for joining rocket parts. Obviously, given how high-strength and lightweight everything for space flight has to be, these welding technologies are not what you can buy in your local hardware store. Prompted by watching Destin’s video, I got curious about welding technologies and innovations more generally.

How I searched for welding technologies and innovations

I am not a mechanical engineer nor a materials scientist. So I simply searched for ‘welding OR welded’ in Mergeflow, and restricted my results to the past three years. Then, I narrowed down on three data sets:

Science Publications

There were more than 8,200 science publications relevant to my search over the past three years. In order to zoom in on what are probably the most interesting or cutting edge ones, I used Mergeflow’s ‘Emerging Technologies’ tags. These emerging technology tags are generated by an algorithm that matches the contents of publications against semantic models of ca. 200 emerging technologies. For my search, the tag cloud looked like this:

Emerging technologies identified by Mergeflow's analytics in scientific publications, in the context of 'welding technologies'.
Emerging technologies identified by Mergeflow’s analytics in scientific publications, in the context of ‘welding technologies’.

Technology Blogs

Unlike scientific publications, technology blogs are written with a more general audience in mind. This makes them a great resource for discovering cutting edge technologies and innovations, particularly if you have no background or training in a field (= me in this case). Similarly to the Scientific Publications data set, I used Mergeflow’s ‘Emerging Technologies’ tags to zoom in.

Research Projects

For one of its data sets, Mergeflow tracks research projects that are funded by various public R&D funding programs. One such funding program that we track is SBIR (Small Business Innovation Research). Since SBIR grants are awarded to small or medium-size companies that are often not widely known (yet), scanning these research projects is a great way to detect under-the-radar companies that do innovative work. For my purposes here, I restricted results to SBIR grants related to welding from the past year. You can access the results from Mergeflow by clicking here.

Please note that my findings are certainly neither representative nor exhaustive. They are merely “food for thought”. In addition, somebody with a technical background in the field might have made a different selection, or searched differently. So if you have come up with a new welding technology that is not on my list, this is my bad, not yours.

Some of the findings are actually not about welding, but about alternatives to welding.

On the top of the list of such alternative technologies is additive manufacturing.

Since my interest was sparked by welding technologies in aerospace, I will start with a finding there, and then move out into other areas.

Large format robotic 3D printer that prints metal structures for rockets

1. Additive manufacturing to make combustion chambers for small rockets

What it is

This project aims to combine two additive manufacturing methods, selective laser melting and magnetic pulse welding, to make bimetallic combustion chambers for small NASA launch vehicles (a.k.a. rockets).

Why it matters

This additive manufacturing method is claimed to be up to 50% cheaper and a lot faster than traditional methods, where combustion chamber parts are first cast and then welded together.

Reference details

Additively manufactured bimetallic combustion chambers for small launch vehicles. SBIR grant awarded to Cornerstone Research Group and ASRC.

Friction stir welding, used to join parts of the Orion spacecraft.

2. Using new welding technologies with conventional CNC machines

What it is

The goal of this project is to further develop a new friction stir welding system so that it can be retrofitted onto commercially available standard CNC machines.

Why it matters

Being able to retrofit the new welding system onto existing CNC machines makes the whole system more scalable and widely available.

Reference details

Robotic bonding system. SBIR grant awarded to Physical Optics Corporation.

ABB welding robot

3. Machine learning to improve welding sequences

What it is

This research proposes using a type of machine learning, reinforcement learning, for welding sequence optimization. In reinforcement learning, the goal is to get an algorithm to master a task. Applied to welding sequence optimization, this means that the goal for the algorithm could be “avoid structural deformation of the workpiece”, for example.

Why it matters

Welding sequence optimization is important in order to minimize structural deformation of the workpiece. But traditional welding sequence optimization algorithms take more than a week to complete. The research proposed here aims to substantially speed up this process. This is essential to early-stage prototyping, for example.

Reference details

Incorporating domain knowledge into reinforcement learning to expedite welding sequence optimization. Research paper.

A solar concentrator, this one at the Australian National University.

4. Solar concentrator units that can power welding

What it is

Solar concentrators generate power by using mirrors that bundle sunlight onto a receiver. The idea behind this project is to develop solar concentrators that empower manufacturing and materials processing applications such as welding.

Why it matters

Welding is power intensive. Solar concentrators can enable communities without access to power grids to do some manufacturing, including welding.

Reference details

Solar concentrator unit for low-cost metal additive manufacturing. SBIR grant awarded to Blueshift.

Attaching an aluminum flange to an aluminum wall, without welding or gluing

5. Joining metals without welding

What it is

This research proposes an electro-chemical etching process called “nanoscale sculpturing” as an alternative to welding and gluing. This process can connect metals with each other, but also metals with polymers.

Why it matters

Since the proposed process works at room temperature, it does not destroy already treated and painted surfaces as welding does. This could make the process particularly well-suited to attach interiors to ships or cars, for example.

Reference details

Joining metals without welding. Making metal surfaces strong, resistant, and multifunctional by nanoscale-sculpturing. Research conducted at the Institute for Materials Science, Kiel University, and Phi-Stone AG.

Graduate student Maximilian Sokoluk, laboratory mechanician Travis Widick, and Professor Xiaochun Li, holding a demonstration bike frame welded using aluminum alloy 7075

6. Using nanoparticles to weld previously unweldable aluminum

What it is

Aluminum alloy 7075 (AA 7075) is very strong and lightweight. But so far it could not be welded because during welding, its constituent materials — aluminum, zinc, copper, and magnesium — create an uneven flow, which results in cracks. Now, in order to solve this issue, a research group at UCLA infused titanium carbide nanoparticles into AA 7075 welding wires.

Why it matters

This new welding process could make AA 7075 available to bicycle or automotive manufacturers, for example, who could then make lighter vehicles that consume less energy.

Reference details

Nanotechnology enables engineers to weld previously un-weldable aluminum alloy. Nanoparticle-enabled phase control for arc welding of unweldable aluminum alloy 7075.

The fabrication process for the embedded silver nanowire (AgNW) nanomesh transparent skin electrode

7. Welding silver nanomesh skin electrodes

What it is

This research has investigated a new mechanical press welding process for making nanomesh shapes. These can be used for manufacturing flexible transparent electrodes.

Why it matters

Silver nanowire has high flexibility, electrical conductivity, and optical transmittance. These properties make it an interesting candidate material for next-generation wearable devices. But some applications, for example displays, additionally require a decrease in haziness, surface roughness, and sheet resistance, as well as an increase in flexibility and substrate adhesion. All of these are claimed to be substantially improved by this research.

Reference details

Invisible silver nanomesh skin electrode via mechanical press welding.

Cryogenic testing of James Webb Space Telescope mirrors

8. Welding negative thermal expansion alloys

What it is

ALLVAR is the only metal alloy that shrinks with increasing temperature, i.e. it shows negative thermal expansion. All other metal expand with increasing temperature. The ultimate goal of this and a follow-up project is to better understand how welding ALLVAR to a positively expanding material (e.g. titanium) affects the stability of the overall resultant structure.

Why it matters

Combining negatively expanding materials with positively expanding ones results in an overall thermally stable structure. Such thermally stable structures are required for space telescopes. Other applications could include storage containers for nuclear waste, for example.

Reference details

Ultra-stable ALLVAR alloy development for space telescopes. SBIR grant awarded to Thermal Expansion Solutions.

A turbine blade sample made of ceramic matrix composites

9. Welding ceramic composites

What it is

This project investigates using commercially available arc welding technologies for joining silicon carbide based ceramics. The specific context of this project are applications in nuclear reactors, where ceramic matrix composites play an important role because they can tolerate very high operating temperatures.

Why it matters

So far, technologies like brazing are used for joining ceramic matrix composites. But the problem with brazing is that the resultant joint material may not be as chemically stable, hermetic, or neutron irradiation tolerant as the original material. Welding may be a better solution, enabling the manufacturing of more complex composites for Generation IV nuclear reactors.

Reference details

Joining of ceramic composites for nuclear applications. SBIR grant awarded to UES.

Textiles made by Natural Fiber Welding

10. Welding natural fibers

What it is

In natural fiber welding, polymers within natural fibers enable fusing and bonding together of natural fibers. This creates higher performance yarns and fabrics, without using glues or resins. The goal of this project is to develop new methods for including indigo dyes into the natural fiber welding process. This process can then be used for manufacturing dyed denim.

Why it matters

Currently, making denim products requires large amounts of water and chemicals. This project could help make this process a lot more sustainable, both economically and ecologically, because the proposed manufacturing process employs closed-loop recycling.

Reference details

Scalable manufacture of natural fiber welded yarn. SBIR grant awarded to Natural Fiber Welding.

screenshot of interactive Mergeflow 360° report on welding technologies.

An interactive 360° view of welding technologies and innovations

Would you like to see the starting-off-point of my search for welding tech and innovations?

Check out a ‘Welding Technologies’ interactive report in Mergeflow

Without a Mergeflow account, you can click on documents in the report. In order to follow the links into Mergeflow, you will need a Mergeflow account. You can get one here.

Featured article image: Space Launch System liquid hydrogen tank bottom, https://commons.wikimedia.org/wiki/File:SLS_Liquid_hydrogen_tank_bottom_in_CELL_E.jpg

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